graybeard vs greybeard

graybeard and greybeard both are nouns.

Word	Noun	Adjective	Verb	Adverb
graybeard	Yes	No	No	No
greybeard	Yes	No	No	No

As nouns, graybeard and greybeard are synonyms defined as:

Other synonyms of graybeard include Methuselah, old man.

graybeard (noun)	greybeard (noun)
a man who is very old	a stoneware drinking jug with a long neck; decorated with a caricature of Cardinal Bellarmine (17th century)
	a man who is very old